Manhole construction



Aug. 18, 1936. A. P. KRAMER MANHOLE CONSTRUCTION Filed May 2, 1952 c 4 5 Z0 /7 2/ l6 INVENTOR. I Hen/we R Ken/151E BY Patented Aug. 18, I936 pairs!) STATES PATENT or ies 2,051,172 r MANHOLE CONSTRUCTION Application May 2,1932, Serial No. 608,634

12 Claims.

My invention relates generally to sewers, storm drains and the like, and more particularly to manhole covers therefor.

An object of my invention is the provision of a novel manhole cover which is structurally characterized by simple, efficient, inexpensive, but substantial means enabling the closure lid of the. cover to be securely locked rigidly to the frame of the cover againstaccidental displacement or vibration by traflic or other objects movingthereover, yet permitting the lid to bereadily released and removed from the frame as: the occasion may require.

Another object of my invention is the provision of a novel manhole cover wherein the-lid is locked to and released from the frame by rotational movement of the lid effected by the use of a suitable prying tool, and wherein novel means is provided for dislodging particles of dirt and other foreign substances which may collect. in the frame ofthe manhole, and discharge such foreign substances into the interiorof the cavity closed by the manhole lid, so as to enable the lid to be freely turned when desired and thereby facilitate its release from, and securement to, the frame. Another object is to provide novel and simple means whereby a closure lid may be. securely locked in a manhole frame against accidental displacement and rattling due to street traflic; and which may be easily and quickly removed therefrom regardless of foreign substances that may have entered the parts while in place or use,

The invention resides in the partsand combination of parts more particularly hereinafter described and pointed out in the appended claims.

Other objects, advantages and features of my;

invention may appear from the accompanying. drawing, the subjoined detail, description and the appended claims. The accompanying drawing illustrates the Invention in a form I at present deem preferable.

Figure 1 is a top plan view of a manhole cover embodying my invention..

Fig. 2 is a vertical axial sectional view taken on line 22-, Fig. 1. V

Fig. 3 is a horizontal sectional view taken on line 3--3, Fig. 2 and looking in the direction of. the arrows. Fig.4 is a top plan view of the manhole frame with the lid removed therefrom.

Fig. 5 is a vertical axial sectional view taken,

on line 5-5, Fig. 4.

Fig. 6; is a bottom plan viewof the lid.

Fig, 7 is a side elevational view of the lid.

Figs. 8 and 9 are diagrammatic views showing the interlocking parts of the manhole cover and the manner in which a prying tool is employed to lock and release the lid from the frame 5 of the manhole cover.

My invention comprises a manhole frame I and. a lid 2, the frame having an annularbase flange 3 from which rises an annular rim 4. The inner periphery of the base flange 3 defines the 10 manhole opening 5 and is bounded by an annular seat 6 preferably supporting an annular packing ring or gasket 1 concentrically with respect to the rim 4.

Projecting from the innerperiphery of the x.

rim 4 are cam members 8 of which in the present instance there are three in number equally spaced apart circumferentially and which have their bottom radial surfaces extending obliquely or spirally in an upward direction with respect to the axis of the frame so as to provide cams t. The cam members are notched radially to define series of lugs or teeth with intervening recesses It? in any of which a suitable prying tool I I is adapted to be extended in a manner and for a purpose to be later fully described. The bottom surfaces of these recesses I 0 incline downwardly and radially inward as indicated at l2 to permit dirt and other foreign substances entering the openings to discharge therefrom into the manhole with which the cover is associated.

The closure lid 2 comprises a top plate l3 suitably reenforced to safely support traffic loads, and provided with air vents I4 and a plurality of peripheral recesses l5 for insertion of a prying tool ll into the series of recesses ll! of the cam members 8 in a manner to be later described. The top plate I3 is of a diameter tobe freely re-' ceived within the rim 4 of the frame I, and

depending from the top plate is an annular rim or skirt IB', the outside diameter of which permits the rim to pass within the cam members 8 and the lower extremity of which is adapted to seat upon the seat provided therefor in the-man'- hole frame I. It will thus be seen that the lid 2 has a rim l6 adapted to be received within the rim 4 of the frame in spaced relation thereto to define an annular space 22' between the rims 4 and I6 and into which space b the spaced apart and circumferentially extending cam members 3 project. Projecting from'the outer periphery of the rim [5 and into the annular space I) are cam 7 members I! of which there are three in number equally spaced circumferentially and having their top radial surfaces extending obliquely or spirally ery of the frame rim Lin advance of the scrapers? in a downward direction with respect to the axis 1 7 of the frame I to provide cams I8 complementary to the cams 9 of the cam members 8 for co-action 7 therewith in'forcing the lid axially in the frame as the lid is'rotated in one direction, and at the same time providing aninterlock between the lid and frame when the coeacting cam surfaces :9

and I8 have been broughtinto engagement with each other. d r "One end of each of the cam members l'I-is 'beveled so as to beitan gentially disposed with .respect to a circle described within the rim of the lid, 'to thereby provide scrapers l9 operable upon rotation of the lid in one direction, to scrape any accumulation of dirt from the inner periphwhen the lid-is being moved to releasable position and thereby aid in easy-rotation of the-lid? y from cam engaging or looking position. lIhe' scrapers 19 are so positioned and'arranged as to direct the removed dirt through passages 20 in the'rim I6 of the lid 2 and into the interior of the cavity closed by themanhol-e lid. The rim I6 is provided withother passages 2| disposed directly below'the pry bar orprying. tool receiv: ing openings l5, and through whichisaid other passages 2|, dirt that maybe dislodged by the pry bar I I from the recesses 10 of the cam mem: bers 8when thepry bar H. is inserted in said recesses I0 through the openings I5, may be dis-.

charged into the manhole;

- In the operation of 'my invention, let it'be as- V sumed that the frame! is. embedded in a street or roadway so that the top edge of'itsrimA is flush with the'street surface, and that the lid" 2is to be applied to the frame to close :the manhole.

' The lid is first placed inthe frame in a position circumferentially relative to. the frame, for its cam members I? to pass .betweenthe adjacent cam. members 8 .of the frame; The lower eX-. tremity of rim !6 oflthelidwill now be resting upon the seat. provided therefor in the manhole frame I, withthe cams l8 of the members 111 'being so disposed vertically with' respect. to the .cams 9 of the members 8,that upon" rotation of the lid bythe prying tool II as hereinafter de.

' scribed, in a counterclockwise direction'as viewed 'in'Fig. 1, the cams 9. and I8 will belbrought into engagement or "contact, with .each other Landthereby 'co-act; in forcingjthe lid axially and downward against itsseat, such as. the gasket 1' .so as to place the latter under compressionand thereby seal the joint between the lid and frame.

V and [8 to function in advancing the lid downward as above described.

In order to enable the lid to be readily rotated with but negligible manual effort, the pry bar H illustrated in Figs.- 8 and 9, is inserted in the" V recess ID of the series of recesses H! which happens to register with one of the recesses IS in thetop plate l3 of the lid'2 as shown in Fig. 8. The pry bar II is now'rocked as a lever in the direction indicated by the arrow a in Fig. 9, to rotate the lid in the frame I to bring the camsv 9 and I8 into engagement'and to cause the cams 9 axially It will be apparent that a tremendous leverage a is applied to rotate the lid' 2jin its frame I, and

- is obtained with the pry bar due to the correla tion of the recesses l5 and recesses I 0, as the fulcrum point of the pry bar inone of said re cesses I8 is in close proximity to-the point of application of the load imposed on the bar by the resistance of the lidto turning, all with respect to the long lever arm provided between-the point 7 of application of the load'and the free endof w'ords a recess I0 is always brought into register with an opening IE to. permit the pry tool II to be operatively'inserted in a recess ID. The pry bar is successivelyinserted in the recess I5 a recess IQ with which it registers, and is manipulated as a' lever to rotate the lid in its frame, this operation being repeated until the annular rim l6'of the lid is'seated with sufficient tightness against its seat due to the cam action of the cam members 8 and I! to lock the lid in its frame. In the fully' seated position of the lid, its top surface will beflush with .the street surface, and the cam members 8 and ll of the frame and lid respectively, will. .co-act informing an interlock to rigidlysecure the lid to the frame. against accidental displacement by traffic loads and pre-.

vent vibration or rattling of the lid. in the frame, yet will permit thelid to be. readily releasedfrom the frame by a reversal of, the above described 7 operation of the'pry-bar as alever. r In' turningthe lid ina'. lockwise direction to release the lid from the framaany'foreignsub stances such as dirt and dust which may have. accumulated on the inner periphery of the frame rim 4 in advance-of the cam members .II will be effectively scraped therefrom by the scrapers l9, and such foreign substances will be directed through the passages!!! so as to discharge the same into the manhole, thus facilitating theremoval of the lid. V i V i Furthermore; should any dirt have "accu'mlated in the recesses Ill" and recesses, it willbe automatically cleared therefrom and discharged into the passages 2| and into the manhole upon the insertion of :the pry bar l I therein, as'the pry bar will force such dirt-through 'therecesses 15 and recesses Ill and along the inclined bottoms -I2,o f theireces'ses IU'andthence-through the passage 2| correlated with the particular recess I5being utilized. 1

; It willthus be manifest that such accumulasibly'preven't'the removal of the lid, will be effec tively disposed of and the otherwise secure lock obtained by the .co-action of the cam surfaces 9 ,tions of dirt as would otherwise hamper and posand 18 may be easi1y broken by application and operation of the pry'tool I I, so that the lid maybe instantly released withoutany appreciable mahual effort. w

What Idesire to claim and secure by Letters Patent is:- d -'1. In a manhole cover construction, the combination of: an annular fixed manhole frame formed upon its innercircumference-with a murality of spaced apart outwardly projecting cams, 5'

the lower edges of which are beveled longitudinally and the upper edges of which are straight, said cams being'serrate'dto provideaseries of notches transversely. thereof; and a manhole 'cover' hav ing an annular extension dependingj:'= into the opening in the manhoIeframe; a. pluralitybf spaced apart outwardly projecting'cams'on the outer circumference of saidf extension 1 and the upper edges of which are beveled longitudinally and adapted when in position to engage the beveled under surface ofthe frame cams; said cover being formed with notches adapted to successively expose therethrough the notches in the frame cams to thereby permit a prying tool to be inserted into said notches to tighten'and loosen the cover in the frame.

2. A manhole cover comprising a frame having an annular rim and seat; a lid having a rim adapted to be received within the rim of the frame in spaced relation thereto to define an annular space between the rims; spaced apart and circumferentially extending cam members projecting from the rims of the frame and lid into said annular space and co-actingin response to rotation of the lid in one direction, to advance the lid axially against said seat; the rim of the lid having passages therethrough at one end of the respective cam members; the said one end of each of the cam members of the lid being provided with scraping edges adapted to engage the inner periphery of the frame rim to scrape foreign substances from the latter and to direct such substances through the openings of the lid rim during rotation of the lid in one direction.

3. A manhole cover comprising a frame having an annular rim and seat; a lid having a rim adapted to be received Within the rim of the frame in spaced relation thereto to define an annular space between the rims; spaced apart and circumferentially extending cam members projecting from the rims of the frame and lid into said annular space and co-acting in response to rotation of the lid in one direction, to advance the lid axially against said seat; the rim of the lid having passages therethrough at one end of the respective cam members; and means on the lid adapted to engage the inner periphery of the frame rim so as to effect scraping of foreign substances therefrom and to direct such removed substances through said passages as the lid is rotated in one direction, whereby to clean such surfaces of the frame to facilitate removal of the lid 4. A manhoie cover comprising a frame having an annular rim and a seat; a lid adapted to be received within the rim of the frame; means on the frame and lid co-acting in response to rotation of the lid in one direction, to advance the lid axially against said seat; and means correlated with the lid for scraping foreign substances from the inner periphery of the frame rim as the lid is rotated in one direction.

5. A manhole cover comprising a frame having an annular rim and a seat; a lid adapted to be received within the rim of the frame; means on the frame and lid co-acting in response to rotation of the lid in one direction, to advance the lid axially against said seat; and means correlated with the lid for scraping foreign substances from the inner periphery of the frame rim as the lid is rotated in one direction; the lid having passages so related to the last means as to receive such foreign substances scraped from the frame rim, for the discharge of the substances into the manhole with which the manhole cover is associated.

6. A manhole cover comprising a frame having an annular rim and a seat; circumferentially spaced apart cam members projecting from the inner periphery of said rim; a lid adapted to be received within said rim and having circumferentially spaced apart cam members with which the cam members of the frame are adapted to co-act in advancing the lid against said seat as the lid is rotated in one direction; the lid having a 'plur'alityof circumferentially spaced openings through which a prying tool is adapted: to be'inserted; the cam members of the frame each having a series of recesses into which the prying tjool isadapted to be .extendedfrom 'said openingsin the lid; therecesses of said series being so related circumferenti'ally to each other and to the said openings'in the lid, that the'recesses of said series will successively register with a different o'neof the lid openings as the lid is rotated, whereby to enable the prying tool to be sucessively inserted: in the lid openings and manipulated as a lever to effect rotation of the lid in one 'directionor the other. p I r 1 7.: A manhole cover'comprising 'a frame having circumferentially spaced cam members; a lid having circumferentially spaced cam members co-acting with the cam'members of the frame to feed the lid axially when rotated relative to the frame; the lid havinga plurality of circumferentially spaced'openings through which a prying tool is adapted to be inserted; the cam members of the frame each having a series of recesses into which the prying tool is adapted to be extended from said openings in the lid; the recesses of said series being so related circumferentially to each other and to the openings in the lid,

that the recesses of said series will successively register with a different one of the lid openings as the lid is rotated, whereby to enable the prying tool to be successively inserted in the lid openings and manipulated as a lever to effect rotation of the lid in one direction or the other.

8. A manhole cover comprising a frame; a lid; means on the frame and lid for feeding the lat- ,ter axially when rotated in the frame; the lid having a plurality of circumferentially spaced openings into which a prying tool is adapted to be inserted; the frame having a circumferential series of recesses so related circumferentially to the openings in the lid as to successively register with a different one of the lid openings as the lid is rotated, whereby to enable the prying tool to be successively inserted in the lid openings and manipulated as a lever to effect rotation of the lid in one direction or the other.

9. A manhole cover comprising a frame; a lid; means on the frame and lid for feeding the latter axially when rotated in the frame; and co,- acting means on the frame and lid with which a prying tool is adapted to co-act in rotating the lid by successive insertions and manipulations of the prying tool as a lever at different locations circumferentially on the lid.

10. A manhole cover comprising a frame having an annular rim and an annular seat; circumferentially spaced apart cam members projecting from the periphery of said rim; a lid adapted to be received within said rim and having 2, depending skirt and circumferentially spaced apart cam members on said skirt with which the cam members of the frame are adapted to co-act to force said skirt against said seat as the lid is rotated in one direction; the lid having a plurality of circumferentially spaced openings through which a prying tool is adapted to be inserted; the cam members on said frame each having a series of recesses into which the prying tool is adapted to be extended from said openings in the lid; said recesses being so related circumferentially to each other and to the openings in the lid, that said recesses will successively register with a different one of the lidopenings as the lid is rotated, whereby to enable the pry- 75 m tool to be successively inserted in the'lid openings and manipulated as a lever ,to effect rotation ofthe lid in one direction orthe other;

said recesses inthe cam members of theframe having their lower portions inclining downwardly having a circumferential series of recessesrfor receiving a prying instrument; an annular seat 'on said frame; a lid adapted to be received in'the frame andhaving an opening adapted to successively.register owiththe frame recesses as the lid is rotated; a skirt depending'from said lid and adapted to seat on said seat; and co-acting means on the frame and skirt for advancing the lid axially to seat said skirt on said seat and for lockby the pry ing the lid in the frame in response to rotation of the lid by manipulation of the pry bar as a lever when inserted in the recesses of. the frame and lid. V V

V 12.,A manhole cover comprising a. hollow frame having a circumferential series of recesses for receiving a prying instrument; a lid adapted to be received in the frame and having an opening adapted to successively register with the frame recesses as the lid is rotated; and co-acting means on the frame and lidfo'r advancing the lid axially and locking the lid in the frame in response to rotation of the lid by manipulation of the pry bar as a lever when inserted in the recesses of the frame and the opening in the lid; the lid having,

passages through which foreign substances forced insertion of the pry bar into said recesses is adapted to be discharged into. the manhole with which the cover is associated.

ARTHUR P. .KRAMER.

bar from the said recesses .upon the V V 

